The present invention relates to apparatus for handling bottles and like articles, particularly of a type suitable in the silk-screen imprinting of such articles.
Conventional screen printing apparatus is easily adapted to the imprinting of articles having a circular cross section, in that the uniform radius of curvature is compatible with a continuous screen transfer operation, and permits the rotation of the article to be easily coordinated with the motion of the screen. It is necessary in the screen printing of articles having less symmetric curvatures, that any motion of the screen be coordinated over time with the surface speed of the article being printed. In the case of oval articles, it is also desirable to provide the capability of presenting both faces of the article to the screen. It is additionally desirable that such apparatus be compatible with articles having a wide range of radii of curvature.
U.S. Pat. No. 4,122,768 discloses an attachment which is employed in connection with a screen printer to handle oval articles during imprinting. This apparatus inverts the article between forward and reverse passes of the screen. These article handling functions are effected purely by mechanical means, a characteristic which imposes undesirable limitations on the repetition rate. Furthermore, a number of machine parts must be replaced to adapt the machine to a new article cross section, thereby requiring additional expense when utilizing such apparatus for a variety of articles.
Accordingly, it is a primary object of the invention to provide article handling apparatus which facilitates the screen printing of articles of oval cross section. A related object is to provide apparatus of this nature which permits the imprinting or other processing of both faces of an oval article.
Another object of the invention is to achieve high repetition rates in the handling of oval articles.
A further object of the invention is the provision of article handling apparatus which is compatible with a variety of article cross-sections. A related object is reducing the required part changes in adapting such machines to different articles.